feat: Always put the favorite contents on the top of the view

This way we can more easily find them and changing the sort order
doesn't move them to the bottom.

src/models/eventmodel.cpp

@@ -187,6 +187,8 @@ QVariant EventModel::data(const QModelIndex& index, int role) const
             }
         } else if (role == SortRole) {
             return index.row();
+        } else if (role == IsFavoritesSectionRole) {
+            return index.row() == OverviewRow::FavoriteRow;
         }
         return {};
     } else if (tag == Tag::Processes) {

src/models/eventmodel.h

@@ -43,6 +43,7 @@ class EventModel : public QAbstractItemModel
         TotalCostsRole,
         EventResultsRole,
         IsFavoriteRole,
+        IsFavoritesSectionRole,
     };
 
     int rowCount(const QModelIndex& parent = {}) const override;

src/models/eventmodelproxy.cpp

@@ -16,6 +16,7 @@ EventModelProxy::EventModelProxy(QObject* parent)
     setSortRole(EventModel::SortRole);
     setFilterKeyColumn(EventModel::ThreadColumn);
     setFilterRole(Qt::DisplayRole);
+    sort(0);
 }
 
 EventModelProxy::~EventModelProxy() = default;
@@ -41,3 +42,18 @@ bool EventModelProxy::filterAcceptsRow(int source_row, const QModelIndex& source
 
     return QSortFilterProxyModel::filterAcceptsRow(source_row, source_parent);
 }
+
+bool EventModelProxy::lessThan(const QModelIndex& source_left, const QModelIndex& source_right) const
+{
+    const auto lhsIsFavoritesSection = source_left.data(EventModel::IsFavoritesSectionRole).toBool();
+    const auto rhsIsFavoritesSection = source_right.data(EventModel::IsFavoritesSectionRole).toBool();
+    if (lhsIsFavoritesSection != rhsIsFavoritesSection) {
+        // always put the favorites section on the top
+        if (sortOrder() == Qt::AscendingOrder)
+            return lhsIsFavoritesSection > rhsIsFavoritesSection;
+        else
+            return lhsIsFavoritesSection < rhsIsFavoritesSection;
+    }
+
+    return QSortFilterProxyModel::lessThan(source_left, source_right);
+}

src/models/eventmodelproxy.h

@@ -18,4 +18,5 @@ class EventModelProxy : public QSortFilterProxyModel
 
 protected:
     bool filterAcceptsRow(int source_row, const QModelIndex& source_parent) const override;
+    bool lessThan(const QModelIndex& source_left, const QModelIndex& source_right) const override;
 };

tests/modeltests/tst_models.cpp

@@ -701,7 +701,26 @@ private slots:
 
         QCOMPARE(proxy.rowCount(), 3);
 
+        {
+            // verify that favorites remain at the top
+            QCOMPARE(proxy.sortOrder(), Qt::AscendingOrder);
+            QCOMPARE(proxy.sortColumn(), 0);
+
+            // favorites on top
+            QVERIFY(proxy.index(0, 0, proxy.index(0, 0)).data(EventModel::IsFavoriteRole).toBool());
+            // followed by CPUs
+            QCOMPARE(proxy.index(0, 0, proxy.index(1, 0)).data(EventModel::CpuIdRole).value<quint32>(), 1);
+
+            proxy.sort(0, Qt::DescendingOrder);
+
+            // favorites are still on top
+            QVERIFY(proxy.index(0, 0, proxy.index(0, 0)).data(EventModel::IsFavoriteRole).toBool());
+            // followed by processes
+            QCOMPARE(proxy.index(0, 0, proxy.index(1, 0)).data(EventModel::ProcessIdRole).value<quint32>(), 1234);
+        }
+
         model.removeFromFavorites(model.index(0, 0, favoritesIndex));
+
         QCOMPARE(proxy.rowCount(), 2);
     }
 
@@ -952,9 +971,9 @@ private slots:
     {
         Data::EventResults events;
         events.cpus.resize(3);
-        events.cpus[0].cpuId = 0;
-        events.cpus[1].cpuId = 1; // empty
-        events.cpus[2].cpuId = 2;
+        events.cpus[0].cpuId = 1;
+        events.cpus[1].cpuId = 2; // empty
+        events.cpus[2].cpuId = 3;
 
         const quint64 endTime = 1000;
         const quint64 deltaTime = 10;
@@ -997,13 +1016,13 @@ private slots:
             event.time = time;
             ++costSummary.sampleCount;
             costSummary.totalPeriod += event.cost;
-            events.cpus[cpuId].events << event;
+            events.cpus[cpuId - 1].events << event;
             return event;
         };
         for (quint64 time = 0; time < endTime; time += deltaTime) {
-            thread1.events << generateEvent(time, 0);
+            thread1.events << generateEvent(time, 1);
             if (thread2.time.contains(time)) {
-                thread2.events << generateEvent(time, 2);
+                thread2.events << generateEvent(time, 3);
             }
         }
         events.totalCosts = {costSummary};